The Problems With Most Multivitamins

When it comes to supplements, you are probably very specific about how you time your pre- and post-workout protein powder, BCAAs, creatine, beta-alanine, etc. After all, you want the most from the supplements that you spend your hard-earned money on. If you’re really smart, then you have already settled on using Pre JYM, Post JYM and Pro JYM because I took all the guess work out of it for you in regards to the ingredients, doses and timing.

Yet when it comes to a multivitamin, most of you probably don’t give much thought to the ingredients, doses or timing. You just grab any ol’ multivitamin that’s on sale and take it. It’s simple and effective. Well, it may be simple, but it is far from effective. You see, 99.99% of the multivitamins sold today are pretty useless. I’m not saying that supplementing with vitamins and minerals is useless, as it’s quite the contrary for those of us who train. What I am saying is that most multivitamin supplements have a multitude of problems that make them less than effective.

The Low Down
Before I get into the details of how most multivitamins do you wrong, let’s cover why a multivitamin, I mean a good multivitamin, should be first on your list of supplements. Research confirms that many athletes and/or those of us who train intensely, lose many critical vitamins and minerals, such as B vitamins, vitamin C, chromium, selenium, zinc, magnesium, iron, and copper. This is due to a variety of factors, such as loss of the minerals in sweat and urine, their increased use for energy production during workouts, as well as their increased use for recovery and protein synthesis following training. Therefore, it’s critical that you get at least the RDA (Recommended Dietary Allowance) or DV (Daily Value) for most minerals, and get far more than these recommendations for most of the vitamins and for certain minerals to optimize your performance and results.

To read my article “Multivitamin/Mineral Roundup,” which covers the many benefits of supplementing with vitamins and minerals, click here: http://www.jimstoppani.com/home/articles/multivitaminmineral-roundup?preview

Multi Madness
When it comes to shopping for a multivitamin, most people are looking for a multi that provides everything they need in one supplement. However, despite the fact that most multivitamins try to romance you with the fact that they provide everything you need, this is the last thing that you should be looking for in a multivitamin.

One major issue with the supplement industry is that few supplement companies have qualified scientists formulating their products. This problem shows up in multivitamins that provide ALL the micronutrients that you need in one product. It sounds convenient to take one dose of a multivitamin a day and be done with it. However, doing so would actually work against your efforts to cover all your bases on vitamin and mineral needs. This is because several micronutrients impair the uptake of other micronutrients. You could say that they essentially cancel each other out. But few supplement companies will actually educate you on this fact. Instead, they prey on the consumer’s wish for convenience and create products based on convenience, not science.

Another problem with the supplement industry is greed. As I’ve taught you regarding pre-workout supplements, post-workout supplements, fat burners and protein powders, most supplement companies create them with the simple goal of making money. So they cut corners and often lie about their products, producing multivitamins that are devoid of critical micronutrients or in far too inadequate doses to be of any real benefit.

This is why I created my own multivitamin/mineral supplement – Vita JYM. I formulated it to avoid all the problems that every other multivitamin has, and provide all the benefits that every other multivitamin doesn’t. The five main problems with most multivitamins are discussed below.

1. Competing Interests
The first big problem with most multivitamins sold today is zinc. I don’t mean that there’s too little of it; the problem is having any zinc in your multivitamin at all. Zinc is so critical, especially for those of us who train, but it can interfere with the absorption of amino acids. Let me say that again: Zinc can inhibit amino acid uptake! Since it’s important to take a multivitamin with a meal, such as breakfast, a multivitamin that includes zinc could interfere with your body’s ability to take up the amino acids from the protein you consumed at breakfast. And that could interfere with muscle growth. That’s the last thing that you want!

Zinc also interferes with copper uptake. Copper is something that you do want in your multivitamin. Zinc induces the intestinal synthesis of a copper-binding protein called metallothionein. Metallothionein traps copper within the cells in the intestines and prevents its absorption into the bloodstream. Plus, iron interferes with zinc absorption, anyway. Since you should have iron in your multivitamin if you train, you should skip the zinc until another time of day. That’s mainly why I recommend taking zinc at night through a ZMA supplement. To read more about ZMA, click on the link: http://www.jimstoppani.com/home/articles/zma-must-have-mineral-for-muscle?preview

Calcium is another big problem in multivitamin supplements. Calcium interferes with zinc, iron and manganese absorption. But I can almost guarantee you that it’s in 99.99% of the multivitamins for sale. Then there’s magnesium, which is also found in most multivitamins. It interferes with manganese absorption as well as with calcium absorption. So these two minerals, calcium and magnesium, should also be completely absent from your multivitamin and be taken separately at another time of day.

Phosphorus is a fourth mineral that you do not want in your multivitamin. The typical diet is already quite rich in phosphorus. Having it in your multivitamin may raise phosphorus levels too high. This is problematic because it can prevent the conversion of vitamin D to its active form,  1,25-dihydroxyvitamin D, in the kidneys. Since this form is the most potent form of vitamin D and provides the majority of its benefits in the body, this can have negative consequences on bone health as well as the numerous other benefits that vitamin D provides, such as better muscle strength and higher testosterone levels.

2. Missing Multis
Another problem with most multis is that they completely skip out on some critical micronutrients altogether. Or the doses that they do provide are at such low levels that they might as well have skipped them altogether.

One common vitamin that is on the MIA list for most multivitamins is vitamin K. Recent research suggests that far more people are deficient in vitamin K than originally believed. Research also shows that supplementing with vitamin K2 alleviates the symptoms of vitamin K deficiency and provides a host of health benefits, including protection against heart disease and cancer, enhanced brain function, skin health, boosting testosterone production and promoting the formation of bone. (For more on the proper from of vitamin K, read “Wrong Form” below).

Another missing or under-dosed micronutrient in many multis is iodine, which is critical for maintaining healthy thyroid function. Since most of the earth’s iodine is found in oceans, iodine deficiency is an important health problem throughout the world. With the demonization of salt/sodium, few people salt their food today and many restaurants use far less salt in their dishes as well. The problem with this is that table salt is iodized (has iodine added) to prevent iodine deficiencies. Research shows that diets that exclude iodized salt, fish and seaweed have been found to contain very little iodine. In fact, studies suggest that iodine intakes have declined in the U.S., Switzerland, and New Zealand. So if your multi is not proving you iodine at 100% of the DV or RDA, then it’s a problem.

Then there’s chromium, which is usually absent or severely under dosed. This is problematic because most diets are quite low in chromium. You could take a separate chromium supplement, but this is one of the minerals that is best to get in your multivitamin. That’s because chromium uptake is enhanced when it’s taken at the same time as vitamin C, which should be in your multi.

Copper is another mineral often missing completely or present in an adequate amount. Since higher intakes of zinc can lead to copper deficiency, and you should be certain to get 30 mg of zinc daily (separate from your multivitamin), it is important to get adequate copper. Evidence suggests that you should get copper and zinc at a 1:10 ratio for optimal health. Since you should be getting in 30 mg of zinc each day from ZMA, your multivitamin should provide a full 3 mg dose of copper.

3. Vitamin and Mineral Dusting
If any of the micronutrients discussed above in the “Missing Multis” section are actually found in your favorite multi, there is a very good chance that they are included at a dose too insignificant to provide any benefit.

As with the “dusting” that I have talked about in pre-workout supplements, many ingredients in a LOT of multivitamin products are severely under dosed. Not only are they under dosed for the hard-training individual, but they often aren’t even provided in adequate dose for the average couch potato. This is because supplement companies want to be able to list them on the Supplement Facts panel.

That way, the uneducated consumer sees the vitamin or mineral listed and assumes the multivitamin has enough of it in there. After all, how many people really know how much copper, iodine, or even B vitamins they need? Many supplement companies take advantage of that fact to make more money by using insignificant doses. Vitamin K, iodine, chromium, copper, selenium and the B vitamins are all typically under dosed, if included at all, in most multivitamins. Other minerals that are also usually under dosed include selenium, molybdenum and manganese. These minerals and vitamins should at the very least provide 100% of the Daily Value (DV) or RDA for them.

4. Wrong Form
Most multis also use cheap, ineffective, or even potentially dangerous forms of certain vitamins and minerals. Consider vitamin A. Vitamin A is often provided in multivitamins mainly as preformed vitamin A (retinol) in the form of retinyl palmitate or retinyl acetate. These forms are rapidly absorbed, but slowly cleared from the body, which can lead to toxicity and liver problems if too much is consumed. The body cannot easily flush out excess vitamin A because it’s fat soluble and is stored in the fat cells. Beta-carotene, on the other hand, is a much safer form of vitamin A to take as it only becomes active vitamin A when needed in the body. To avoid possible vitamin A toxicity, your multivitamin should provide all of its vitamin A from beta-carotene.

If you’re lucky to find a multivitamin that provides some Vitamin K, there is a very good chance that it is in the form of or vitamin K1, phylloquinone, also known as phytonadione. This form comes from plants, specifically green leafy vegetables, such as lettuce and spinach, as well as broccoli. Although this form of vitamin K is fine, it is not that necessary in a multivitamin since few people are vitamin K1 deficient.

The other main form of vitamin K, vitamin K2, menaquinone, appears to be the more critical form to supplement with. The menaquinones have repeating 5-carbon units on the side chain of the molecule. These forms of vitamin K are designated menaquinone-n (MK-n), such as MK-4 or MK-7, where the n stands for the number of 5-carbon units. Of the menaquinones, menaquinone-4 (MK-4) and menaqionone-7 (MK-7) are the most critical to supplement with. MK-4 is found in meat and dairy (significantly higher in meat and dairy from grass-fed cows), as well as egg yolks. MK-7 comes from fermented products, such as cheese, sauerkraut and nato (fermented soybeans).

The body requires so little vitamin K1 that just about everyone gets enough from their diet. Vitamin K2, on the other hand is required at a much higher dose and provides more benefits. While both vitamins K1 and K2 appear to be involved in blood clotting, K2 provides benefits that go far beyond that. Research suggests that being deficient in vitamin K may lower testosterone levels and that supplementing with MK-4 can increase testosterone production. This appears to be due to vitamin MK-4’s ability to activate specific enzymes in the testicles that are critical for testosterone production.

Chromium is another mineral that is typically given in a cheap, less-effective form, such as chromium chloride. The problem is that since this mineral tends to be low in athletes and those who train, you need a good dose in a form that’s readily absorbed, such as chromium picolinate. Chromium picolinate is a combination of chromium and picolinic acid. The addition of the picolinic acid enhances the uptake of chromium.

And then there’s vitamin B12. Many companies will try to tell you that methylcobalamin is the best form of B12 to use. While this is one of the active forms of B12, it just one of the active forms. There are two active of forms. The other active form of B12 is adenosylcobalamin, also known as dibencozide. While some multivitamins provide both of these, the problem is the stability of these active forms. There is evidence that they are not very stable and therefore, do not provide the actual dose of B12 listed on the label. The only way to consume a stable form of B12 that is readily converted to both methylcobalamin and adenosylcobalamin in the body is by taking the cyanocobalamin form of B12. Click on the link below to read more on cyanocobalamin: http://www.jimstoppani.com/home/articles/cyanocobalamin-b12-in-vita-jym?preview

5. Add Ons
Another problem is that other specialized ingredients, such as “male-enhancing” supplements, joint-healing supplements, performance supplements, omega-3 fats and other healthy fats, and even fat-burning ingredients are added on. This has become a popular trend in multivitamins. Sadly, it’s not because it’s effective supplementation. It’s a popular trend among supplement companies only because once one company duped enough supplement consumers into falling for it and buying a lot of these multivitamins, other companies followed their lead.

These add-on ingredients are usually not at the proper dose that they should be to be effective. So, if you truly feel you need a “male-enhancing” supplement, or supplements to aid joint recovery, or anything else, buy a separate supplement.

Rethink Your Multivitamin
Now that you are armed with this info on the real science behind taking vitamins and minerals, go back and analyze your favorite multivitamin. I must warn you that you may want to make sure that you are sitting down when you do so. That’s because I can almost guarantee you that your favorite multi is guilty of at least four of the five common problems that I discussed above. Sad, but true.

Next, compare my Vita JYM label to the label of your favorite multi. This will help you to see the info that I covered in this article in its application. Now you can see how I meticulously formulated Vita JYM to avoid all the problems that hamper most multivitamins and how I created the perfect multivitamin formula for men and women who train hard like I do.

Next, click on the link below to read my article “How to Take Vita JYM” for more in-depth information on supplementing Vita JYM along with calcium, vitamin D3 and zinc and magnesium via ZMA, and why its important to take them as I have outlined in the article: http://jymsupplementscience.com/how-to-take-vita-jym/

Most people report feeling and seeing a difference in their energy levels, mood, performance and even physique after only a few weeks of supplementing with Vita JYM as I prescribe taking it. That’s because taking the critical micronutrients you need in the right doses, supplied in the right forms, and taken at the right times makes a world of difference in the way that your body functions. I might argue that nailing down your micronutrient supplementation with Vita JYM is even more critical than focusing on your workout nutrition with Pre JYM, Pro JYM and Post JYM. But ideally, you should be taking all four.

References
Gibson, J. C., et al. Nutrition status of junior elite Canadian female soccer athletes. Int J Sport Nutr Exerc Metab. 2011 Dec;21(6):507-14.

Czaja, J., et al. Evaluation for magnesium and vitamin B6 supplementation among Polish elite athletes. Rocz Panstw Zakl Hig. 2011;62(4):413-8.

Martinović, J., et al. Oxidative stress biomarker monitoring in elite women volleyball athletes during a 6-week training period. J Strength Cond Res. 2011 May;25(5):1360-7.

Zaĭtseva IP. Efficiency of using vitamin-mineral complexes in the prevention of iron-deficiency states in athletes. Gig Sanit. 2010 Jul-Aug;(4):66-9.

Louis, J, et al. Vitamin and mineral supplementation effect on muscular activity and cycling efficiency in master athletes. Appl Physiol Nutr Metab. 2010 Jun;35(3):251-60.

Clarkson, P. M. Effects of exercise on chromium levels. Is supplementation required? Sports Med. 1997 Jun;23(6):341-9.

Clarkson P. M. and Haymes E. M. Trace mineral requirements for athletes. Int J Sport Nutr. 1994 Jun;4(2):104-19.

Telford, R. D., et al. The effect of 7 to 8 months of vitamin/mineral supplementation on the vitamin and mineral status of athletes. Int J Sport Nutr. 1992 Jun;2(2):123-34.

Dam, B. V. Vitamins and sport. Br J Sports Med. 1978 Jun;12(2):74-9.

Mursu, J., et al. Dietary supplements and mortality rate in older women: The Iowa women’s health study. Archive of Internal Medicine 171(18):1625-1633, 2011.

Li, K., et al. Vitamin/mineral supplementation and cancer, cardiovascular, and all-cause mortality in a German prospective cohort (EPIC-Heidelberg). Eur J Nutr. 2012 Jun;51(4):407-13.

Arul, A. B., et al. Multivitamin and mineral supplementation in 1,2-dimethylhydrazine induced experimental colon carcinogenesis and evaluation of free radical status, antioxidant potential, and incidence of ACF. Canadian Journal of Physiology and Pharmacology 90(1):45-54, 2012.

Park, Y. et al. Intakes of vitamins A, C, and E and use of multiple vitamin supplements and risk of colon cancer: a pooled analysis of prospective cohort studies. Cancer Causes Control. 2010 Nov;21(11):1745-57.

Rautiainen, S., et al. Multivitamin use and the risk of myocardial infarction: a population-based cohort of Swedish women. American Journal of Clinical Nutrition 2010.

Pocobelli, G., et al. Use of supplements of multivitamins, vitamin C, and vitamin E in relation to mortality. American Journal of Epidemiology, 2009.

Xu, C., et al. Multivitamin use and telomere length in women. American Journal of Clinical Nutrition 89(6):1857-1863, 2009.

Peters, U., et al. Serum selenium and risk of prostate cancer-anested case-control study. The American Journal of Clinical Nutrition 85(1):209-217, 2007.

Dobson, A. et al. A study of the cost effects of daily multivitamin for older adults. The Lewin Group, 2003.

Barringer, T. A., et al. Effect of a Multivitamin and Mineral Supplement on Infection and Quality of Life: A Randomized, Double-Blind, Placebo-Controlled Trial. Annals of Internal Medicine 138(5):365–371, 2003.

Macpherson, H. et al. Memory improvements in elderly women following 16 weeks treatment with a combined multivitamin, mineral and herbal supplement – A randomized controlled trial. Psychopharmacology 220(2): 351-365, 2012.

Haskell, C. F., et al. Effects of a multi-vitamin/mineral supplement on cognitive function and fatigue during extended multi-tasking. Hum Psychopharmacol. 2010 Aug;25(6):448-61.

Harris, E., et al. The effect of multivitamin supplementation on mood and stress in healthy older men. Human Psychopharmacology: Clinical and Experimental 26(8): 560-567, 2011.

Kennedy, D. O., et al. Effects of high-dose B vitamin complex with vitamin C and minerals on subjective mood and performance in healthy males. Psychopharmacology (Berl). 2010 Jul;211(1):55-68.

Haskell, C. F., et al. Cognitive and mood effects in healthy children during 12 weeks supplementation with multi-vitamin/minerals. Br J Nutr. 2008 Nov;100(5):1086-96.

Li, Y., et al. Effects of multivitamin and mineral supplement on adiposity, energy expenditure and lipid profiles in obese Chinese women. International Journal of Obesity 34(6):1070-1077, 2010.

Major, G.C., et al. Multivitamin and dietary supplements, body weight and appetite: results from a cross-sectional and a randomised double-blind placebo-controlled study. Br J Nutr. 2008 May;99(5):1157-67.

Brandão-Neto, J., et al. Zinc acutely and temporarily inhibits adrenal cortisol secretion in humans. A preliminary report. Biol Trace Elem Res. 1990 Jan;24(1):83-9.

Brilla, L. R. and Conte, V. Effects of a Novel Zinc-Magnesium Formulation on Hormones and StrengthJournal of Exercise Physiology online. 3(4): 2000.

Brilla, L. R. and Haley, T. F. Effect of magnesium supplementation on strength training in humans. J Am Coll Nutr. 1992 Jun;11(3):326-9.

Cinar, V., et al. Effects of magnesium supplementation on blood parameters of athletes at rest and after exercise. Biol Trace Elem Res. 2007 Mar;115(3):205-12.

Cinar, V., et al. The effects of magnesium supplementation on thyroid hormones of sedentars and Tae-Kwon-Do sportsperson at resting and exhaustion. Neuro Endocrinol Lett. 2007 Oct;28(5):708-12.

Cordova, A. and Navas, F. J. Effect of training on zinc metabolism — changes in serum and sweat zinc concentrations in sportsmen. Ann Nutr Metab 1998:42:274-82.

Evans, G. W. and Johnson, E. C. Effect of iron, vitamin B-6 and picolinic acid on zinc absorption in the rat. J Nutr 1981:111: 68-75.

Freake, H. C., et al. Actions and Interactions of Thyroid Hormone and Zinc Status in Growing Rats. J. Nutr. 131: 1135–1141, 2001.

Golf, S. W., et al. On the significance of magnesium in extreme physical stress. Cardiovasc Drugs Ther 1998:12:197-202.

Haralambie, G., et al. Serum zinc in athletes in training. Int J Sports Med. 1981 Aug;2(3):135-8.

Kilic, M., et al. Effect of fatiguing bicycle exercise on thyroid hormone and testosterone levels in sedentary males supplemented with oral zinc. Neuro Endocrinol Lett. 2007 Oct;28(5):681-5.

Kilic, M., et al. The effect of exhaustion exercise on thyroid hormones and testosterone levels of elite athletes receiving oral zinc. Neuro Endocrinol Lett. 2006 Feb-Apr;27(1-2):247-52.

Kilic, M., et al. Effect of zinc supplementation on hematological parameters in athletes. Biol Trace Elem Res. 2004 Jul;100(1):31-8.

Konig, D., et al. Zinc, iron, and magnesium status in athletes—influence on the regulation of exercise-induced stress and immune function. Exerc Immunol Rev 1998:4:2-21.

Kwun, I. S., et al. Marginal zinc deficiency in rats decreases leptin expression independently of food intake and corticotrophin-releasing hormone in relation to food intake. Br J Nutr. 2007 98(3):485-9.

Mahalanabis, D., et al. Randomized, double-blind, placebo-controlled clinical trial of the efficacy of treatment with zinc or vitamin A in infants and young children with severe acute lower respiratory infection. American Journal of Clinical Nutrition 79(3): 430-436, 2004.

Mocchegiani, E., et al. Zinc, metallothioneins, and longevity–effect of zinc supplementation: zincage study.Ann N Y Acad Sci. 2007 Nov;1119:129-46.

Mossad, S. B. Effect of zincum gluconicum nasal gel on the duration and symptom severity of the common cold in otherwise healthy adults. QJM. 2003 Jan;96(1):35-43.

Persigehl, M. Changes in the serum zinc concentration in different metabolic situations. Z Klin Chem Klin Biochem. 1974 Apr;12(4):171-5.

Sazawal, S., et al. Zinc supplementation reduces the incidence of acute lower respiratory infections in infants and pre-school children: a double-blind, controlled trial. Pediatrics 102:1–5, 1998.

Shankar, A.H., et al. Zinc and immune function: The biological basis of altered resistance to infection. Am J Clin Nutr 68: 447S–463S, 1998.

Sprietsma, J. E. Modern diets and diseases: NO–zinc balance. Under Th1, zinc and nitrogen monoxide (NO) collectively protect against viruses, AIDS, autoimmunity, diabetes, allergies, asthma, infectious diseases, atherosclerosis and cancer. Medical Hypotheses(1999) 53(1): 6–16.

Theberge, C. S. and Volpe, S. L. Effect of Zinc Depletion and Repletion on Resting Metabolic Rate and Zinc Status in Healthy Male and Female. New England American College of Sports Medicine Annual Meeting, 2003.

VanLoan, M. D., et al. The effects of zinc depletion on peak force and total work of knee and shoulder extensor and flexor muscles. Int J Sport Nutr 1999:9:125-135.

Wada, L. and King, J. C. Effect of low zinc intakes on basal metabolic rate, thyroid hormones and protein utilization in adult men. J Nutr. 1986 Jun;116(6):1045-53.

Wichnik, A., et al. Magnesium aspartate as a cardioprotective agent and adjuvant in tocolysis with betamimetics. Animal experiments on the kinetics and calcium antagonist action of orally administered magnesium aspartate with special reference simultaneous vitamin B administration. Z Geburtshilfe Perinatol 1982:186:326-34.

O’Brien KO, Zavaleta N, Caulfield LE, Wen J, Abrams SA. Prenatal iron supplements impair zinc absorption in pregnant Peruvian women. J Nutr. 2000;130(9):2251-2255. (PubMed)

Fung EB, Ritchie LD, Woodhouse LR, Roehl R, King JC. Zinc absorption in women during pregnancy and lactation: a longitudinal study. Am J Clin Nutr. 1997;66(1):80-88. (PubMed)

Wood RJ, Zheng JJ. High dietary calcium intakes reduce zinc absorption and balance in humans. Am J Clin Nutr. 1997;65(6):1803-1809. (PubMed)

McKenna AA, Ilich JZ, Andon MB, Wang C, Matkovic V. Zinc balance in adolescent females consuming a low- or high-calcium diet. Am J Clin Nutr. 1997;65(5):1460-1464. (PubMed)

Mendoza, C., et al. Effect of a micronutrient fortificant mixture and 2 amounts of calcium on iron and zinc absorption from a processed food supplement. Am J Clin Nutr. 2004 Feb;79(2):244-50.

Rodriguez Yoldi, M. C., et al. Effect of zinc on L-threonine transport across the jejunum of rabbit. Biol Trace Elem Res. 1993 May-Jun;37(2-3):269-79.

Brzozowska, A., et al. Interaction of iron, zinc and copper in the body of animals and humans. Rocz Panstw Zakl Hig. 1989;40(4-6):302-12.

Fischer, P. W., et al. Effects of zinc on mucosal copper binding and on the kinetics of copper absorption. J Nutr. 1983 Feb;113(2):462-9.

Fischer, P. W., et al. The effect of dietary zinc on intestinal copper absorption. Am J Clin Nutr. 1981 Sep;34(9):1670-5.

Oestreicher, P. and Cousins, R. J. Copper and zinc absorption in the rat: mechanism of mutual antagonism. J Nutr. 1985 Feb;115(2):159-66.

Levander, O. A. and Whanger, P. D. Deliberations and evaluations of the approaches, endpoints and paradigms for selenium and iodine dietary recommendations. J Nutr. 1996;126(9 Suppl):2427S-2434S.

Food and Nutrition Board, Institute of Medicine. Iodine. Dietary reference intakes for vitamin A, vitamin K, boron, chromium, copper, iodine, iron, manganese, molybdenum, nickel, silicon, vanadium, and zinc. Washington, D.C.: National Academy Press; 2001:258-289.

Remer, T., et al. Increased risk of iodine deficiency with vegetarian nutrition. Br J Nutr. 1999;81(1):45-49. (PubMed)

Davidsson, L. Are vegetarians an ‘at risk group’ for iodine deficiency? Br J Nutr. 1999;81(1):3-4.

Zimmermann, M. B., et al. Increasing the iodine concentration in the Swiss iodized salt program markedly improved iodine status in pregnant women and children: a 5-y prospective national study. Am J Clin Nutr. 2005;82(2):388-392. (PubMed)

Thomson, C. D., et al. Urinary iodine and thyroid status of New Zealand residents. In: Roussel AM, Anderson RA, Favier A, eds. Trace Elements in Man and Animals. Vol 10. New York: Kluwer Academic Press; 2000:343-344.

Hollowell, J. G., et al. Iodine nutrition in the United States. Trends and public health implications: iodine excretion data from National Health and Nutrition Examination Surveys I and III (1971-1974 and 1988-1994). J Clin Endocrinol Metab. 1998;83(10):3401-3408.

Lukaski, H. C. Magnesium, zinc, and chromium nutriture and physical activity. Am J Clin Nutr. 2000;72(2 Suppl):585S-593S.

Rubin, M. A, et al. Acute and chronic resistive exercise increase urinary chromium excretion in men as measured with an enriched chromium stable isotope. J Nutr. 1998;128(1):73-78.

Theuwissen, E., et al. Vitamin K status in healthy volunteers. Food & Function 5(2):229-234, 2014.

Theuwissen E., et al. The role of vitamin K in soft-tissue calcification. Adv Nutr. 2012 Mar 1;3(2):166-73.

Shirakawa, H., et al. Vitamin K deficiency reduces testosterone production in the testis through down-regulation of the Cyp11a a cholesterol side chain cleavage enzyme in rats. Biochim Biophys Acta. 2006 Oct;1760(10):1482-8. Epub 2006 Jun 6.

Ito, A., et al. Menaquinone-4 enhances testosterone production in rats and testis-derived tumor cells. Lipids Health Dis. 2011 Sep 13;10:158.

Badmaev, V., et al. Piperine, An Alkaloid Derived From Black Pepper, Increases Serum Response Of Beta-Carotene During 14-Days Of Oral Beta-Carotene Supplementation Nutrition Research 19(3):381-388, 1999.

http://www.jimstoppani.com/home/articles/build-your-own-multivitaminmineral